verb
also rar·i·fy -rəˌfī
( -ed/-ing/-es )
Etymology: rarefy from Middle English rarefien, from Middle French rarefier, modification (influenced by -fier -fy) of Latin rarefacere, irregular from rarus + facere to make, do; rarify from Middle English rarifien, from Medieval Latin rarificare, from Latin rarus + -ificare -ify — more at rare , do
transitive verb
1. : to make rare, thin, porous, or less dense : expand or enlarge without adding any new portion of matter to — opposed to condense
the expansive power of moisture rarified by heat — T.B.Macaulay
2. : to make more spiritual, refined, tenuous, or abstruse
their wits are refined and rarefied — Ben Jonson
intransitive verb
: to become less dense or gross : become rare
Synonyms: see thin